Method of and apparatus for forming corner pads

ABSTRACT

A method of and apparatus for forming corner pads utilizing a plurality of plies, each of which is adapted to be folded into a trihedral angle arrangement, wherein the plies are successively fed into juxtaposed relation while adhesive is applied to predetermined surfaces of certain of the plies, and the plies are successively formed into trihedral angle arrangements while being successively placed in contiguous, nesting relationship to secure the nested plies together by the adhesive to maintain the same in a collective trihedral angle arrangement.

April 3, 1973 B. L. DOLL 3,725,170

METHOD OF AND APPARATUS FOR FORMING CORNER PADS Filed May 11, 1970 5 Sheets-Sheet 1 CUTTlNG AND SUCCESSWELY APPLYWG FORMING Scowzmca FEENNG D ABHEsn BQ Pues IN O PLIE5 PLIES To LAE-S CGRNE-R PAB J L L Z6 27 F 50 3\ INVENTOR. BRENBAN L. DOLL.

BYWEZM% M5 44 ATTORNEYS April 3, 1973 B. L. 001.1. 3,725,170

METHOD OF AND APPARATUS FOR FORMING CORNER PADS Filed May 11, 1970 5 Sheets-Sheet 2 K) INVENTOR. PBEENBAN L. DOLL ws im ATTORNEYS April 3, 9 B. L. 001.1. 3,725,170

METHOD OF AND APPARATUS FOR FORMING CORNER PADS Filed May 11, 1970 5 Sheets- Sheet 3 INVENTOR. BRENDAN L. boLL ATTORNEYS B. L. DOLL April 3, 1973 METHOD OF AND APPARATUS FOR FORMING CORNER PADS 5 Sheets-Sheet 4 Filed May 11, 1970 INVENTOR. BAN L. o L

Brae-N ATTORNEYS B. L. DOLL April 3, 1913 METHOD OF AND APPARATUS FOR FORMING CORNER PADS s Sheets-Sheet 5 Filed May 11, 1970 3 O mb w. L N A D N E E B United States Patent 3,725,170 METHOD OF AND APPARATUS FOR FORMING CORNER PADS Brendan L. Doll, Patterson, N.C., assignor to Cellu Products Company, Patterson, N.C. Filed May 11, 1970, Ser. No. 36,332 Int. Cl. 365d /44, 25/24 US. Cl. 156-417 13 Claims ABSTRACT OF THE DISCLOSURE A method of and apparatus for forming corner pads utilizing a plurality of plies, each of which is adapted to be folded into'a trihedral angle arrangement, wherein the plies are successively fed into juxtaposed relation while adhesive is applied to predetermined surfaces of certain of the plies, and the plies are successively formed into trihedral angle arrangements while being successively placed in contiguous, nesting relationship to secure the nested plies together by the adhesive to maintain the same in a collective trihedral angle arrangement.

The present invention relates to a method of and apparatus for forming corner pads for protecting the corners of furniture or the like during shipment or other handling, and more particularly to such a method of and apparatus for forming trihedral corner pads in a substantially continuous, automated manner.

It is the usual practice in the shipment or other handling of furniture and the like to utilize corner pads of suitable shock-absorbent material over each of the corners thereof to protect the same from damage. The most common corner pad, utilized for this purpose is formed by manually folding a unitary blank of corrugated paperboard material which is suitably cut and scored to facilitate its being folded into the corner pad. Such corner pads are almost universally in the shape of a trihedral angle since this shape has been found to provide the desired protection with a minimum of material.

While providing adequate shock absorption and protection to the corners of furniture and the like, conventional corner pads require an excessive amount of paperboard material for a given amount of shock absorption since there is considerable waste of the paperboard material in the fabrication thereof. Further, no automated method and apparatus have been found for forming trihedral corner pads, and therefore only manual operations have been utilized in the fabrication thereof. These manual operations are very time consuming, and contribute materially, along with the aforementioned waste of material, to an excessive cost of producing conventional corner pads.

With the foregoing in mind, it is an object of the present invention'to provide a method of and apparatus for forming corner pads which obviate the deficiencies of the prior manual operations of forming corner pads heretofore utilized.

It is a more specific object of the present invention to provide a method of and apparatus for forming corner pads which may be substantially automated and thereby a significant reduction in the cost of manufacture can be achieved.

It is still another object of the present invention to provide a method of and apparatus for forming corner pads wherein the production of corner pads is substantially increased over the production of conventional corner pads.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings in which-- 3,725,170 Patented Apr. 3, 1973 FIG. 1 is an illustrative flow diagram of certain of the methods of the present invention;

FIG. 2 is an exploded plan view of a blank suitably cut and scored for the formation of a corner pad in accordance with the method and by the apparatus of the present invention;

FIG. 3 is a perspective view of one portion of the blank shown in FIG. 2;

FIG. 4 is an isometric view of a finished corner pad formed in accordance with the method and by the apparatus of the present invention;

FIG. 5 is a fragmentary plan view of an apparatus illustrating the features of the present invention;

FIG. 6 is a side elevational view of the apparatus shown in FIG. 5;

FIG. 7 is a front elevational view of the apparatus shown in FIGS. 5 and 6;

FIG. 8 is a vertical sectional view taken substantially along line 8-8 in FIG. 6;

FIG. 9 is a fragmentary, exploded isometric view of a portion of the apparatus shown in FIGS. 5, 6 and 7 and illustrating the ply feeding means and portions of the forming means; and I FIG. 10 is an enlarged vertical sectional view taken substantially along line 10-10 in FIG. 6.

Referring now to the drawings, there is illustrated in FIG. 4 a corner pad 20 which is also shown and described r in my co-pending application, Ser. No. 729,157, filed May 15, 1968, and entitled Corner Paid. and Blanlg, which will issue at Pat. No. 3,511,464 on May 12, 1970. As illustrated, corner pad 20 comprises a plurality of plies 21, 22, 23 and 24, each of which is arranged in a trihedral angle arrangement, and then placed in contiguous, nesting relation with another ply. The plies are secured together by suitable means,such as by adhesive 25 (FIG. 3). One of the desirable characteristics of corner pad 20 and of the method of the present invention is that the corner pad can be formed with a minimum waste of material and in most instances can be formed without any waste of material.

One example of how the plies 21-24 of corner pad 20 can be formed is illustrated in FIG. 2 and, as there shown, a sheet of any suitable shock absorbent material which is sufficiently flexible to be folded while still providing the required shock absorbency, is suitably cut into four generally L-shaped portions 21', 22', 23' and 24'. Due to the manner of cutting and the shape of these portions, the entire area of the sheet is utilized in the portions and there is no waste. Of course, there are other. ways in which the plies can be formed, as for example from a web of material instead of a sheet, from a much larger sheet, or from a narrower sheetor web of a width scored along lines 21a, 21b, 210'; 22a, 22b, 220'; 23a,

23b, 23c; and 24a, 24b, 240. This cutting and scoring step is indicated at 26 in the flow diagram of FIG. 1.

As stated above, one of the desirable characteristics of the present invention is that the corner pad 20 can be formed in a substantially continuous, automated manner. To this end, the cutting and scoring of the plies and the forming of the cut scored plies into the corner pad 20 may proceed in one continuous operation, but it is also contemplated by the present invention that the plies can be cut and scored in a separate operation and suitably stored until they are desired to be formed into corner pads 20.

After the cutting and scoring of the plies, the same are successively fed into juxtaposed relation, as indicated at 27 in FIG. 1. Also, the adhesive 25 is applied to predetermined surfaces of certain of the plies (indicated at 30 in FIG. 1) and preferably, the adhesive is applied while the plies are being fed into juxtaposed relation. Finally, the plies are formed into a corner pad 20 (indicated at 31 in FIG. 1) by forming each of the plies into a trihedral angle arrangement and then placing the thusly formed plies into contiguous, nesting relation. These steps of the present method will be described in more detail in connection with the description of the illustrated embodiment of an apparatus of the present invention.

The apparatus, illustrated in FIGS. -10, is generally indicated at 32 and includes a suitable base 33 and front, rear, and top frame members 34, 35 and 36 (FIG. 6). A pair of storage means, generally indicated at 40 and 41 in FIG. 5, are supported in spaced apart relation by the frame members and are adapted to store a suitable stack 42, 43 of the plies for formation into the corner pads 20. The supply means 40, 41 are substantially identical in construction and therefore only supply means 40 will be described in detail.

Supply means 40 comprises a center support member 44 which is adapted to be received within the included angle of the generally L-shape of the plies and to support the plies thereby, and side support members 45, 46 disposed on opposite sides of the center support member 44 and at a slightly higher elevation. Side support members 45, 46 are adapted to engage the ends of the legs of the generally L-shaped plies when the same are positioned in the supply means. A slide 47 is mounted on center support member 44 for movement toward the forward end of the supply means 40 and is suitably biased in this direction by a weight 50 (FIG. 6) connected thereto by a line 51 which extends over a pulley 52. The stack of plies 42 is thereby urged toward the forward end of the supply means 40 so that the plies may be successively withdrawn and fed into juxtaposed relation for formation into corner pads.

A plate 53 is mounted immediately in front of and extends between the two supply means 40 and 41 and has openings 54, 55 therein at the forward ends of these supply means, respectively, through which the plies are successively delivered. Ply positioning means is provided at each of the openings 54, 55 and includes a bar or plate 56 extending parallel to plate 53 and across the upper portions of the openings 54, 55 to engage the top portion of each ply. A pair of ply restraining pads 57, 58 are alsomounted at openings 54, 55, respectively, for engaging the lower portion of each ply. Bar 56 and pads 57, 58 are spaced from the forward surface of plate 53 a distance corresponding substantially to the thickness of one ply and are adjustably mounted to vary this spacing to accommodate plies of varying thickness. The plies are successively delivered through the openings 54, 55 until they engage the bar 56 and one set of pads 57, 58 which position each successive ply for being fed along the plate 53 with the top portion thereof between the plate 53 and bar 56 into position to be formed into a corner pad 20.

The successive feeding of the plies is accomplished by feeding means 60 (FIG. 9) which comprises a slide 61 slidably mounted on a track member 62 which in turn is mounted on the front frame member 34. The slide 61 includes a pair of upstanding feeding members 63, 64 which include first portions 63a, 64a extending upwardly at an acute angle to the vertical, and second portions 63b, 64b extending upwardly from the upper ends of first portions 63a, 6411 and generally perpendicular thereto. Second portions 63b, 64!; extend parallel to the distal, inclined upper edges of the plies in the supply means 40 and 41. Feeding members 63, '64 also include third portions 63c, 64c mounted on second portions 63b, 64b and extending therealong. The proximal edges of third portions 63c, 640 are recessed from the proximal edges of second portions 63b, 64b to form ply receiving notches which receive and hold the edge portion of the ply during feeding.

Ply hold back members 65, 66 are respectively carried by the feeding members 63, 64 for holding the plies in the supply means 40, 41 rearwardly of the plate 53 during the inactive or rearward stroke of each of the feeding members 63, 64 to prevent the feeding member from striking and damaging the plies in the supply means. Also, suitable guide rollers '67, 68 are carried by the upper ends of the feeding members 63, 64 and are received between bar 56 and a guide bar 69 mounted adjacent thereto.

The slide 61 is reciprocated by a suitable drive means illustrated as including a slide block 70 connected to the slide 61 and mounted for reciprocation on a track member 71. Slide block 70 is connected by a suitable link 72 to one end of a crank arm 73 (FIG. 7) which is pivotally mounted on the front frame member 34 and is connected by a link 74 to an eccentric 75 (FIG. 7) mounted on a drive shaft 76. Therefore, upon rotation of the eccentric 75, the slide 61 is reciprocated back and forth along the track member 62 and feeds successive plies from each of the supply means 40, 41 in alternation.

Plate 53 also has a medial opening 77 therein and forming means, generally indicated at 80 in FIG. 6, is provided between the supply means 40 and 41 at this medial opening. Forming means 80 includes a female forming and nested ply receiving means 81, which is illustrated as including a cylinder 82 mounted for rotation about its longitudinal axis by mounting means 83. Mounting means 83 includes a pair of cradle members 84, 85 mounted on the top frame member 36 and having a plurality of supporting rollers 86, 87 mounted thereon which are received in grooves (not shown) in the cylinder 82 to hold the cylinder in position and prevent axial movement thereof. Cylinder 82 is rotated by drive means including a gear 90 mounted around cylinder 82, an idler gear 91 meshing with gear 90 and a drive gear 92 mounted on drive shaft 76.

Cylinder 82 has three plate members 93, 94, mounted therein and extending rearwardly therefrom a substantial distance. Plate members 93, 94, 95 include forward portions 93a, 94a and 95a extending perpendicular to the longitudinal axis of the cylinder 82 and defining restraining means adapted to engage the plies adjacent the outer periphery thereof. The plate members 93, 94, 95 also include portions 93b, 94b, 95b which extend generally parallel to the longitudinal axis of cylinder 82, but which are arranged relative to each other such that they collectively define a triangle which corresponds in shape and size to the triangle of the base of each of the trihedral angle arrangements into which the plies are formed so that the thusly formed plies may be received within the space bounded by the portions 93b, 94b and 95b within cylinder 82.

Forming means 80 also includes male forming means which cooperates with the female forming means 81 for forming the plies into the trihedral angle arrangements. Male forming means 100 includes a forming member 101 which is mounted for pivotal movement by a shaft 102 mounted in spaced bearings 103. Member 101 is generally C-shaped and has a lower end portion 101a which is adapted to strike each of the plies at As a ply is moved into position by the feeding means 60, the same is positioned between the male forming means 100 and the female forming means 81 with the included angle facing downwardly. In timed relation to the operation of the feeding means 60, the male forming member 101 is moved downwardly about the axis of the shaft 102 to bring the portion 101a into sharp contact with the ply and to force the ply rearwardly against the portions 93a, 94a and 95a which restrain rearward movement of the peripheral portions of the ply while the male forming member continues to force the central portion of the ply rearwardly which folds the ply along the score lines therein into a trihedral angle arrangement. Once the ply has been folded into the trihedral angle arrangement, the same will slide into the area bounded by the portions 93b, 94b and 95b within the cylinder 82 and will be forced rearwardly within this area until the same is brought into contiguous nesting relationship with the previously formed ply. The male forming member 101 is then withdrawn by the spring 104 to permit the next ply to be moved into position for formation.

The attitude of at least one ply in each corner pad is varied relative to the other plies so that the edges of this L-shaped ply which abut when the ply is formed into a trihedral angle arrangement will be out of registry with the abutting edges of the other plies. In the illustrated embodiment, this is accomplished by rotating cylinder 82 a fraction of a revolution for certain plies being I formed. More specifically, the cylinder 82 is rotated one-third of a revolution during the formation of each ply so that the abutting edges of adjacent plies are out of registry.

Preferably, adhesive is applied to predetermined surfaces of certain of the plies to secure the plies together to maintain the same in contiguous nesting relationship and so that they define a collective trihedral angle arrangement. To this end, adhesive applying means 110 and 111 are disposed between the respective supply means 40 and 41 and the forming means 80. As illustrated, adhesive applying means 110 and 111 include spraying heads I112, 113 for spraying adhesive of a suitable type, preferably hot melt adhesive but other types may be used, onto the forwardly facing surfaces of certain of the plies. The spraying heads 112, 113 are connected by suitable pipes 114, 115 to a suitable pressurized source of adhesive, and are preferably constructed so as to spray adhesive onto the plies in two vertically spaced lines (as seen in FIG. 3) as the plies are fed past the spraying heads.

The spraying heads 112, 113 are controlled by means of solenoids 116, 117 which have suitable wiring extending to a control means. Preferably, this control means controls the application of adhesive to the plies in such a manner that the application of adhesive controls the number of plies in the corner pad being formed. For example, if the corner pad is to be of two-ply construction, adhesive would be applied only to alternate plies fed past the spraying heads 112, 113. If the corner pad is to be of three-ply construction, adhesive would be applied to two successive plies and the third ply would not have any adhesive applied thereto. This would be true for any number of plies, with adhesive being applied to a number of successive plies equal to one less than the number of plies desired to be included in the corner pad. Of course, the foregoing statements apply only to the application of adhesive to one surface of the ply, but a suitable sequence of adhesive application to both sides or the like and controls therefor will be readily apparent to a workman in this field.

The control means for the spraying heads 112, 113 includes a control panel 120 (FIG. 7) having a selector knob 12 having four (4) illustrated positions 121a, 12 1b, 121c and 121d. The control means also includes control switches 122, 123, 124, 125, 126, 127 and 128 (FIG. 10) which are selected by rotation of the knob 121 and which are controlled by suitable cams 130-134 which are driven 6 by a chain and sprocket drive system from the drive shaft 76. By rotating the cams at different speeds by utilizing sprockets of different sizes and by having different configurations therefor, the timing and interval of actuation of the various switches and hence the spraying heads 1112, 113 can be controlled relative to the feed of the plies to control the adhesive application in the desired manner set forth above.

After formation into the trihedral angle arrangements and the placement into contiguous, nesting relationship, the nested plies are forced rearwardly within the space between the portions 93b, 94b, b of plate members 93, 94, 95 by the addition of newly formed plies to the forward end of the space. The time interval required for the nested plies to move from the forward end of this space to the rearward end thereof is ample for the adhesive to become set, or dry as the case may be, and the nested plies exit from this space as finished corner pads 20 (FIG. 5). Preferably, conveyor means (FIGS. 5 and 6) is provided beneath the rearward end of plate members 93, 94 and 95 for receiving and conveying the finished corner pads away from the machine for use or packaging.

It is therefore believed apparent that the present in vention provides a novel method of and apparatus for forming corner pads whereby the corner pads may be formed in a substantially continuous, automated manner and with little or no waste of material and a considerably higher rate of production than has heretofore been possible.

In the drawings and specification there have been set forth the preferred embodiments of the invention, and although specific terms are employed, they are use in a generic and descriptive sense only and not for purposes of limitation.

What is claimed is:

1. A method of forming a corner pad for protecting the corners of furniture or the like during shipment or other handling comprising the steps of,

successively forming a plurality of separate and independent plies into trihedral angular arrangements, placing the thusly formed plies in contiguous, nesting relationship, and

securing the nested plies together by applying adhesive to at least one of the contiguous surfaces of adjacent plies to maintain the same in a collective trihedral angular arrangement.

2. A method according to claim 1 wherein the forming of the plies into the trihedral angle arrangement includes successively feeding the plies into juxtaposed relation and successively folding the plies along score lines therein int othe trihedral angle arrangements.

3. A method according to claim 1 including cutting and scoring a sheet of material to form a plurality of independent plies adapted to be folded along score lines therein into the trihedral angle arrangements.

4. A method according to claim 3 wherein the cutting of the sheet of material comprises cutting the sheet into a plurality of generally L-shaped portions, and the scoring of the sheet comprises forming score lines therein which meet at the point of the included angle of the L-shape so that when the plies are formed into the trihedral angle arrangements the apex thereof will be at this point of the included angle and the edges of the L-shaped portion defining the included angle Will be brought into abutting relation.

5. A method of forming a corner pad for protecting the corners of furniture or the like utilizing a plurality of separate and independent generally L-shaped plies, each of which is adapted to be folded into a trihedral angle arrangement, said method comprising the steps of successively feeding the plurality of plies into juxtaposed relation while applying adhesive to predetermined surfaces of certain of the plies, and

successively forming the plurality of plies into trihedral angle arrangement while placing the thusly formed plies in contiguous, nesting relationship so that the adhesive on the surfaces of the certain plies is brought into contact with the contiguous surfaces of the adjacent plies to secure the plies together and maintain the same in a collective trihedral angle arrangement.

6. A method according to claim wherein the application of adhesive further comprises spraying adhesive onto the predetermined surfaces.

7. A method according to claim '5 wherein the application of adhesive includes applying adhesive to one surface of all plies forming the corner pad except one of the terminal plies.

8. A method according to claim 5 wherein the formation of the plies into trihedral angle arrangements includes bringing the edges of the plies defining the included angle of the L-shape into abutting relation, and including varying the attitude of at least one ply in the corner pad relative to the other plies so that the abutting edges of at least one ply will be out of registry with the abutting edges of the other plies.

applying adhesive to predetermined surfaces of only I I certain of the plies with the number of plies to which adhesive is applied determining the number of plies in each corner pad, and

successively forming the plies into trihedral angle arrangements while placing the plies in contiguous, nesting relationship so that the adhesive on the surfaces of the certain plies is brought into contact with the contiguous surfaces of the adjacent plies to secure these plies together and maintain the same in a collective trihedral angle arrangement with the plies to which adhesive was not applied defining a division between adjacent corner pads upon subsequent removal thereof from 'the nested relationship.

10. A method according to claim 9 wherein the feeding of the plies includes withdrawing the plies one-at-a-time from a stack of plies within a storage means.

11. A method according to claim 9 including varying the attitude of at least one ply in each corner pad relative to the other plies so that the abutting edges of at least one ply will be out of registry with the abutting edges of the other plies.

12. A method according to claim 9 including varying the attitude of each ply relative to the adjacent ply so that the abutting edges thereof will be out of registry.

'13. A method according to claim 12 wherein the varying of the attitude of successive plies comprises rotating the nested plies a fraction of a revolution after the placement of each formed ply therein and prior to the placement of the next formed ply therein.

References Cited UNITED STATES PATENTS ROBERT F. BURNETT, Primary Examiner M. E. McCAMlSH, Assistant Examiner US. Cl. X.R. 

